Fixed CoW RuntimeError in DecodingTask.run() (openai#240)

Author: CorentinJ

whisper/decoding.py

@@ -615,7 +615,7 @@ def run(self, mel: Tensor) -> List[DecodingResult]:
         n_audio: int = mel.shape[0]
 
         audio_features: Tensor = self._get_audio_features(mel)  # encoder forward pass
-        tokens: Tensor = torch.tensor([self.initial_tokens]).expand(n_audio, -1)
+        tokens: Tensor = torch.tensor([self.initial_tokens]).repeat(n_audio, 1)
 
         # detect language if requested, overwriting the language token
         languages, language_probs = self._detect_language(audio_features, tokens)